Bipolar electrosurgical scissors

ABSTRACT

Bipolar electrosurgical scissors for treating biological tissue include first and second scissor blades. A shearing surface and cutting edge of each blade is electrically neutral. The scissors include a pair of electrical connections for receiving electrical currents of opposing polarities. Each blade includes at least one first electrode and at least one second electrode positioned on a surface opposite the shearing surface. The at least one first electrode on the first blade and the at least one second electrode on the second blade are coupled to the first electrical connection. The at least one second electrode on the first blade and the at least one first electrode on the second blade are coupled to the second electrical connection. In a first energized state, the electrical connections deliver electrical current only to the first electrodes. In a second energized state, the electrical connections deliver electrical current to all of the electrodes.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/460,292, filed on Jul. 27, 2006, issued on Sep. 2, 2008 and is nowU.S. Pat. No. 7,419,490, the entire disclosure of which is herebyincorporated by reference as if set forth in full herein.

BACKGROUND OF THE INVENTION

This invention relates generally to the field of minimally invasivesurgery, and in particular to a hand-held, bipolar laparoscopic devicefor electrical or mechanical cutting of biological tissue and forcoagulation of the tissue.

Nearly every open and laparoscopic surgical procedure requires thecutting and sealing of vascularized tissue. To reduce or minimizebleeding of the tissue, conventional surgical scissors have begun to bereplaced with electrically energized scissors in monopolar and bipolarconfigurations, each offering certain advantages and disadvantages.Monopolar refers to a configuration where a return electrode is coupledto a patient, typically in the form of a patch coupled to the patient'sskin, so that only one active electrode need be carried on the surgicalinstrument. With the monopolar technique, a concentrated electricalcurrent is delivered from the active electrode on the instrument totargeted tissue, causing coagulation that stops bleeding. Theelectricity then disperses and flows through the patient en route to thereturn electrode attached to the patient's skin. Bipolar refers to aconfiguration wherein the instrument carries both the active and returnelectrodes, delivering energy to tissue between the two electrodes.

Monopolar electrosurgical instruments facilitate several surgicalfunctions, such as cutting tissue, coagulating tissue to stop bleeding,or concurrently cutting and coagulating tissue. The surgeon can apply acurrent whenever the conductive portion of the instrument is inelectrical contact with the patient, permitting the surgeon to operatewith monopolar instruments from many different angles. However, asstated above, monopolar electrosurgical instruments do have somedrawbacks, especially when used for laparoscopic procedures.

During laparoscopic monopolar electrosurgery, the view of the surgicalfield is somewhat constricted. The surgeon operates from the exterior ofthe patient's body using remote instrumentation. The manipulation ofinstruments and tissue is based on magnified images that are relayedfrom a camera connected to a laparoscope and displayed on a monitor. Theactive electrode may be in close proximity to other conductiveinstruments and to tissue, and may result in stray electrical currentbeing transmitted to unseen tissue off the extended shaft of the remotelaparoscopic instruments, possibly leading to thermal injury to thepatient.

Stray currents may cause patient injury outside the laparoscope's viewvia direct coupling, insulation failure, or capacitive coupling. Directcoupling occurs when the active electrode touches another metalinstrument within the patient, such as in the abdomen, transferringenergy to the second instrument and possibly injuring tissue with whichit comes in contact.

Insulation failure occurs when the insulated shaft of the electrode,which is designed to protect against the release of stray electricalcurrent, becomes compromised due to insulation breakdown. The breakdownalong the unseen shaft of an activated electrode can allow electricalcurrent to leak into surrounding non-targeted tissue, causing unobserveddamage.

Capacitive coupling occurs when electrical current is induced from theactive electrode to nearby conductive material, despite intactinsulation. During electrosurgery, the charge on the active electrodeswitches from highly positive to highly negative at a very highfrequency. The rapidly varying electrical field around the activeelectrode is only partially impeded by electrical insulation and createsstray electrical currents by alternately attracting and repelling ionsin surrounding body tissue. The movement of electrically charged ions incapacitively coupled tissue can cause currents that can heat tissuesufficiently to produce a burn.

In comparison to monopolar surgical instruments, such as monopolarscissors, the electrical current in a bipolar arrangement is notrequired to travel long distances through the patient before returningto the return electrode, thereby greatly reducing the minute risk ofaccidental burns. Instead, a bipolar electrode arrangement applieselectrical current only between two energized cutting blades which areclosely spaced and always within the field of view of the surgeon. Abipolar arrangement also requires less electrical power than a monopolararrangement because the electrical current disperses through a muchsmaller volume of tissue. More importantly, a bipolar arrangementeliminates the possibility of accidental burns through an insulationfailure of the active shaft and greatly reduces the risk of directcoupling and capacitive coupling. However, bipolar instruments requirethe surgeon to carefully position the instrument to ensure that both theactive and return electrodes are in electrical contact with the patientbefore applying a current. This may limit the range of motion and theangle from which the surgeon can effectively use the bipolar instrument.

There are several variations for placement of electrodes onelectrosurgical scissors that allow electrical current to flow throughthe cut tissue. For example, the exterior surface of one shearing membercan include an active electrode while the exterior surface of the othershearing member can include a return electrode. In this configuration,electrosurgical current can flow from the exterior surface of one blade,through the cut tissue, to the exterior surface of the other blade.

In another variation, each of the two shearing surfaces includes anactive electrode, while each of the two exterior surfaces includes areturn electrode, or vice versa. In this configuration, electricalcurrent can flow from each shearing surface, through the cut tissue, toan exterior surface, or vice versa.

Apart from mechanical cutting, the practicality of monopolar scissorsmakes them more favorable to surgeons. Monopolar scissors not onlypermit a surgeon to coagulate tissue between the blades prior to cuttingthe tissue mechanically, but they also permit the surgeon to dissectthin connective tissue electrically by moving one blade in a sweep-likemotion over the tissue. Monopolar scissors also permit electrosurgicalcoagulation of small blood vessels that are cut open during a mechanicalcutting process. This is typically performed by energizing the tissuewith the exterior surface of one of the scissor blades.

Conventional bipolar scissors also permit electrical coagulation andcutting of the tissue between the blades, but they do not allow for thecommon practice to utilize one blade for dissection of tissue by movingthe blade in a sweep-like motion over the tissue. Conventional bipolarscissors also do not allow for simultaneous coagulation of tissuebetween the blades and surrounding tissue, or coagulating the tissue byenergizing it with the exterior surface of one of the blades. This isdue to the common approach to separate the high frequency (HF)coagulation and mechanical cutting action both spatially andfunctionally by arranging the active, electrically conductive, radiofrequency (RF) electrodes on the outside of each electrically conductiveblade, while being electrically insulated through insulators, such asceramic or plastic.

One improved bipolar scissors includes blades having electrodes on theinner surface of each blade with the electrodes being connected to thesame pole to avoid a short circuit between the mating inner faces of theblades. The outer surface of each of the blades includes at least twoelectrodes connected to opposite poles, meaning that at least one of theelectrodes on the outer surface of each blade is connected to the samepole as the electrode on the inner surface of the blade. With thesescissors, all of the electrodes are energized simultaneously and thereare no means to have less than all of the electrodes energized whenapplying electrical current to the electrodes. In this manner, it is notpossible to coagulate only the tissue between the blades. If anelectrical current is applied while cutting the tissue, the surroundingtissue is also coagulated.

SUMMARY OF THE INVENTION

The deficiencies of the prior art are overcome with the presentinvention, which includes a bipolar electrosurgical scissors for use intreating biological tissue. The bipolar electrosurgical scissorsincludes a first and second scissor blade. Each of the first and secondscissor blades has a shearing surface, an opposed surface that isopposite the shearing surface, a cutting edge, a first, proximal end,and a second, distal end. The shearing surface and cutting edge of eachof the scissor blades is electrically neutral. The shearing surface ofthe first blade and the shearing surface of the second blade face eachother and interface with each other. A pivot pin pivotally couples thefirst scissor blade to the second scissor blade at a position that isproximal to the shearing surfaces of the first and second scissorblades. The bipolar electrosurgical scissors also include a firstelectrical connection for receiving an electrical current of a firstpolarity and a second electrical connection for receiving an electricalcurrent of a second polarity, which is opposite to the first polarity.Each of the first and second scissor blades includes at least oneexposed first electrode and at least one exposed second electrodepositioned on the opposed surface of the respective scissor blade andextending lengthwise along the length of the respective scissor blade.The at least one first electrode on the first scissor blade is coupledto the first electrical connection. The at least one second electrode onthe first scissor blade is coupled to the second electrical connection.The at least one first electrode on the second scissor blade is coupledto the second electrical connection. The at least one second electrodeon the second scissor blade is coupled to the first electricalconnection. In a first energized state, the first electrical connectiondelivers electrical current only to the at least one first electrode onthe first scissor blade and the second electrical connection deliverselectrical current only to the at least one first electrode on thesecond scissor blade. In a second energized state, the first electricalconnection delivers electrical current to the at least one firstelectrode on the first scissor blade and to the at least one secondelectrode on the second scissor blade. In the second energized state,the second electrical connection delivers electrical current to the atleast one second electrode on the first scissor blade and to the atleast one first electrode on the second scissor blade.

In another aspect, the distance between the at least one first electrodeand the at least one second electrode on the opposed surface of each ofthe first and second scissor blades is sufficient to prevent electricalarcing between the electrodes, and small enough to permit simultaneousconnection between the tissue and two respective electrodes havingopposing polarity.

In another aspect, each of the first and second scissor blades includesa laminated structure having a first layer, a second layer, a thirdlayer, a fourth layer and a fifth layer. The first layer on each of thefirst and second scissor blades coincides with the shearing surface andcutting edge of the respective scissor blade and includes a first,shearing surface and a second, opposed surface. The first surface of thefirst layer forms the shearing surface of the respective blade. Thesecond layer is coupled to the second surface of the first layer. Thesecond layer is electrically nonconductive and includes a material thatinsulates against electrical current. The third layer is coupled to thesecond layer on the side opposite the first layer. The third layer iselectrically conductive and exposed portions of the third layer form theat least one first electrode of the respective scissor blade. The fourthlayer is coupled to the third layer on the side opposite the secondlayer. The fourth layer is electrically nonconductive and includes amaterial that insulates against electrical current. The fifth layer iscoupled to the fourth layer on the side opposite the third layer. Thefifth layer is electrically conductive and exposed portions of the fifthlayer form the at least one second electrode of the respective scissorblade. In another facet, the second layer of each of the first andsecond scissor blades completely separates the third layer from thefirst layer and provides insulation between the third layer and thefirst layer of the respective scissor blade. Likewise, the fourth layerof each of the first and second scissor blades completely separates thethird layer from the fifth layer and provides insulation between thethird layer and the fifth layer of the respective scissor blade. Inanother facet, the electrically insulating material of the second andfourth layers of the first and second scissor blades has sufficientdielectric strength to substantially prevent electrical breakdown of theelectrically insulating material. In another facet, the exposed surfacesof the third layer of each of the first and second scissor blades formsat least two first electrodes and the exposed surfaces of the fifthlayer of each of the first and second scissor blades form at least onesecond electrode. In another facet, the exposed surfaces of the fifthlayer of each of the first and second scissor blades forms one secondelectrode positioned between the at least two first electrodes of therespective scissor blade.

In another aspect, the first layer of each of the first and secondscissor blades includes a first edge surface, which coincides with thecutting edge, and a second edge surface. In another facet, the scissorsinclude an electrically insulating coating on the first layer of each ofthe first and second scissor blades. The electrically insulating coatingcovers the shearing surface, the cutting edge, the portion of the firstedge surface proximate the shearing surface and the portion of thesecond edge surface proximate the shearing surface. The first layer ofeach of the blades includes at least one first electrode positioned oneach of the first and second edge surfaces at the portions of the firstand second edge surfaces that are proximate the opposed surface of therespective first layer. The portions of the first and second edgesurfaces of the first layers on the first and second scissor blades thatform the first electrodes on the first layers are not covered with theelectrically insulating coating. In another facet, the electricallyinsulating coating on the shearing surfaces of the first and secondscissor blades includes an amorphous diamond-like carbon. In anotherfacet, the exposed surfaces of the third layers of each of the first andsecond scissor blades form at least two second electrodes of therespective blade. The exposed surfaces of the fifth layer of each of thefirst and second scissor blades form at least one first electrode of therespective blade. In another facet, in the first energized state, thefirst electrical connection delivers electrical current only to thefirst electrodes positioned on the first layer of the first scissorblade and the second electrical connection delivers electrical currentonly to the first electrodes positioned on the first layer of the secondscissor blade. In another facet, the distance between the firstelectrodes on the first and second edge surfaces of adjacent firstlayers of the first and second scissor blades, with the scissors in aclosed condition, is sufficient to prevent electrical arcing between theelectrodes. The distance between the first electrodes on the first andsecond edge surfaces of adjacent first layers of the first and secondscissor blades, with the scissors in a closed condition, is small enoughto permit simultaneous connection between the tissue and a firstelectrode on the first scissor blade and a first electrode on the secondscissor blade.

In another aspect, each of the first and second scissor blades of thebipolar electrosurgical scissors includes an insulating body having aprimary surface that corresponds with the shearing surface of the bladeand a secondary surface that corresponds with the opposed surface of theblade. Each of the first and second scissor blades also includes ashearing layer that has a first, shearing surface, a second, opposedsurface, and the cutting edge. The opposed surface of the shearing layeris coupled to the primary surface of the insulating body. The at leastone first electrode and the at least one second electrode are coupledto, inlayed into, or deposited onto the secondary surface of theinsulating body of each of the first and second scissor blades. Thefirst and second electrodes are positioned in an alternatingrelationship with the first and second electrodes on the second scissorblade corresponding with the first and second electrodes on the firstscissor blade. In another facet, the distance between the at least onefirst electrode and the at least one second electrode on the opposedsurface of each of the first and second scissor blades is sufficient toprevent electrical arcing between the electrodes in an openconfiguration, and small enough to permit simultaneous connectionbetween the tissue and two respective electrodes having opposingpolarity. In another facet, the material that forms the electricallyinsulating body of each of the first and second scissor blades hassufficient dielectric strength to substantially prevent electricalbreakdown of the electrically insulating body.

In another aspect, the shearing layer of each of the first and secondscissor blades includes a first edge surface and a second edge surface.The first edge surface coincides with the cutting edge of the respectiveblades. In another facet, the scissors include an electricallyinsulating coating on the shearing layer of the first and second scissorblades. The electrically insulating coating covers the shearing surface,the cutting edge, the portion of the first edge surface proximate theshearing surface and the portion of the second edge surface proximatethe shearing surface. The scissors also include at least one firstelectrode positioned on each of the first and second edge surfaces ofthe shearing layer of each of the first and second scissor blades at theportion of the respective edge surface that is proximate the opposedsurface of the respective shearing layer. In another facet, theelectrically insulating coating on the shearing surfaces of the firstand second scissor blades includes an amorphous diamond-like carbon. Inanother facet, in the first energized state, the first electricalconnection delivers electrical current only to the first electrodespositioned on the shearing layer of the first scissor blade and thesecond electrical connection delivers electrical current only to thefirst electrodes positioned on the shearing layer of the second scissorblade. In another facet, the distance between the first electrodes onthe first and second edge surfaces of adjacent shearing layers of thefirst and second scissor blades, with the scissors in a closedcondition, is sufficient to prevent electrical arcing between theelectrodes. The distance between the first electrodes on the first andsecond edge surfaces of adjacent shearing layers of the first and secondscissor blades, with the scissors in a closed condition, is small enoughto permit simultaneous connection between the tissue and a firstelectrode on the first scissor blade and a first electrode on the secondscissor blade.

These and other features and advantages of the invention will beclarified with a description of the embodiments and reference to theassociated drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view depicting a bipolar electrosurgicalscissors of the present invention incorporated into laparoscopicscissors;

FIG. 2 is an end view of the blades of the bipolar electrosurgicalscissors of FIG. 1 depicting the blades in an open condition withbiological tissue positioned between the blades and the scissorsenergized in a first energized state with just the tissue between theblades being energized;

FIG. 3 is a perspective view of the bipolar electrosurgical scissors ofthe present invention incorporated into conventional surgical scissors;

FIG. 4 is an end view of the blades of the bipolar electrosurgicalscissors of FIG. 1 depicting the blades in an open condition withbiological tissue positioned between the blades and the scissorsenergized in a second energized state with the tissue both between theblades and surrounding the blades being energized;

FIG. 5 is an end view, in cross-section, depicting the blades of thebipolar electrosurgical scissors with the blades in a laminatedconfiguration;

FIG. 6 is an end view, in cross-section, depicting the blades of thebipolar electrosurgical scissors with the electrodes being coupled ontoan insulated body portion of the blades;

FIG. 7 is an end view, in cross-section, depicting the blades of thebipolar electrosurgical scissors with the electrodes being inlayed intoan insulated body portion of the blades;

FIG. 8 is an end view, in cross-section, depicting the blades of thebipolar electrosurgical scissors with the electrodes being depositedonto an insulated body portion of the blades;

FIG. 9 is an end view, in cross-section, depicting the blades of thebipolar electrosurgical scissors with the blades in a laminatedconfiguration, similar to FIG. 5 but having additional electrodes on thefirst layer of the blades;

FIG. 10 is an end view, in cross-section, depicting the blades of thebipolar electrosurgical scissors with the electrodes being coupled ontoan insulated body portion of the blades, similar to FIG. 6 but havingadditional electrodes on the shearing layer of the blades;

FIG. 11 is an end view, in cross-section, depicting the blades of thebipolar electrosurgical scissors with the electrodes being inlayed intoan insulated body portion of the blades, similar to FIG. 7 but havingadditional electrodes on the shearing layer of the blades;

FIG. 12 is an end view, in cross-section, depicting the blades of thebipolar electrosurgical scissors with the electrodes being depositedonto an insulated body portion of the blades, similar to FIG. 8 buthaving additional electrodes on the shearing layer of the blades;

FIG. 13 is a side view depicting the electrosurgical scissors of FIG. 11with the scissors energized in the second energized state to coagulatetissue with the side of the blade;

FIG. 14 is a side view depicting the electrosurgical scissors of FIG. 11with the scissors energized in the second energized state to dissecttissue with the electrodes on the shearing layers of the blades;

FIG. 15 is an end view of the blades of the bipolar electrosurgicalscissors of FIG. 12 depicting the blades in an open condition withbiological tissue positioned between the blades and the scissorsenergized in a first energized state with just the tissue between theblades being energized;

FIG. 16 is an end view of the blades of the bipolar electrosurgicalscissors of FIG. 11 depicting the blades in an open condition withbiological tissue positioned between the blades and the scissorsenergized in a second energized state with the tissue both between theblades and surrounding the blades being energized; and

FIG. 17 is a side view depicting the electrosurgical scissors of FIG. 6with the scissors energized in the second energized state to dissecttissue with the side of the blade.

DESCRIPTION OF THE INVENTION

The invention and its various embodiments can now be better understoodwith the following detailed description wherein illustrated embodimentsare described. It is to be expressly understood that the illustratedembodiments are set forth as examples and not by way of limitations onthe invention.

Referring to FIGS. 1-2, the invention includes bipolar electrosurgicalscissors 20 for use in treating biological tissue 22. The scissors 20include a first scissor blade 24 and a second scissor blade 26. Each ofthe first and second blades 24, 26 includes a shearing surface 28, anopposed surface 30 positioned opposite the shearing surface, a cuttingedge 32, a first, proximal end 31, and a second, distal end 33. A pivotpin 34 pivotally couples the first blade 24 to the second blade 26 at aposition proximal the shearing surfaces 28 of the first and secondblades. The shearing surfaces 28 of the first and second blades 24, 26face each other and interface with each other. As depicted in FIG. 1,the scissors 20 may be part of a laparoscopic surgical instrument 36.Alternatively, as depicted in FIG. 3, the scissors 20 may be part ofconventional electrosurgical shears 38 to be used in conventional, opensurgery.

With continuing reference to FIG. 1, the scissors 20 include first andsecond electrical connections 40, 42. The first electrical connection 40receives an electrical current of a first polarity, and the secondelectrical connection 42 receives an electrical current of a secondpolarity that is opposite to the electrical current of the firstpolarity.

Referring to FIG. 2, each of the first and second scissor blades 24, 26includes at least one first electrode 44 and at least one secondelectrode 46. Each of the first and second electrodes 44, 46 ispositioned on the opposed surface 30 of the respective blade. The atleast one first electrode 44 on the first blade is coupled to the firstelectrical connection 40 (FIG. 1). The at least one second electrode 46on the first blade 26 is coupled to the second electrical connection 42(FIG. 1). The at least one first electrode 44 on the second blade 26 iscoupled to the second electrical connection 42. The at least one secondelectrode 46 on the second blade 26 is coupled to the first electricalconnection 40. Each of the first and second electrodes 44, 46 includes aportion that is exposed on the opposed surface 30 of the respectiveblade 24, 26. The first and second electrodes 44, 46 extend lengthwisealong the length of the opposed surfaces 30 of the first and secondblades 24, 26. The shearing surface 28 of each of the blades 24, 26 isnot coupled to either of the first and second electrical connections 40,42. Moreover, the shearing surface 28 of each of the first and secondblades 24, 26 is electrically neutral. As will be described in moredetail below, the shearing layer of each of the blades may be coupled toopposing first and second electrodes 44, 46, and first and second edgesurfaces of the shearing layers of each of the blades 24, 26 may includea first electrode. As will also be described in more detail below, thefirst and second electrodes 44, 46 are all separated by an insulatingmaterial.

With continuing reference to FIG. 2, in a first energized state, thefirst electrical connection 40 delivers electrical current only to theat least one first electrode 44 on the first scissor blade 24 and thesecond electrical connection 42 delivers electrical current only to theat least one first electrode 44 on the second scissor blade 26. In asecond energized state (see FIG. 4), the first electrical connection 40(FIG. 1) delivers electrical current to the at least one first electrode44 on the first blade 24 and to the at least one second electrode 46 onthe second blade 26 while the second electrical connection 42 (FIG. 1)delivers electrical current to the at least one second electrode 46 onthe first blade 24 and to the at least one first electrode 44 on thesecond blade 26.

Referring to FIG. 5, the first and/or second scissor blade 24, 26 mayinclude a laminated structure. FIG. 5 depicts each of the first andsecond blades 24, 26 including the laminated structure including atleast a first, shearing layer 48, a second layer 50, a third layer 52, afourth layer 54 and a fifth layer 56.

The first layer 48 coincides with the shearing surface 28 and cuttingedge 32 of the scissor blades 24, 26. The first layer 48 includes afirst, shearing surface 49 and a second, opposed surface 51, and is madeof a material capable of forming a desirable cutting edge, such as ametal or other materials that are well known in the art. As statedabove, the shearing surface 28 of each of the first and second blades24, 26 is electrically neutral. Thus, the first layer 48 is not coupledto either of the first or second electrical connections 40, 42. Thesecond layer 50 is coupled to the second surface 51 of the first layer48. The third layer 52 is coupled to the second layer 50 on the sideopposite the first layer 48. The third layer 52 is electricallyconductive. The fourth layer 54 is coupled to the third layer 52 on theside opposite the second layer 50. The fifth layer 56 is coupled to thefourth layer 54 on the side opposite the third layer 52. The fifth layer56 is electrically conductive.

With continuing reference to FIG. 5, the third layer 52 of each of thescissor blades 24, 26 includes exposed portions 58 that form the atleast one first electrode 44 of the first and second blades. The thirdlayer 52 on the first blade 24 is coupled to the first electricalconnection 40 (FIG. 1) and the third layer 52 on the second blade 26 iscoupled to the second electrical connection 42 (FIG. 1). The secondlayer 50 completely separates the third, conductive layer 52 from thefirst, neutral layer 48. The second layer 50 is electricallynonconductive and is formed of a material that insulates againstelectrical current to prevent the current delivered to the third layerfrom flowing to the first layer.

The fifth layer 56 includes exposed portions 60 that form the at leastone second electrode 46 on each of the first and second scissor blades24, 26. The fifth layer 56 on the first blade 24 is coupled to thesecond electrical connection 42 and the fifth layer 56 on the secondblade 26 is coupled to the first electrical connection 40. The fourthlayer 54 completely separates the fifth, conductive layer 56 from thethird, conductive layer 52, and the third layer has opposing polarity tothe fifth layer. The fourth layer 54 is electrically nonconductive andis formed of a material that insulates against electrical current toprevent shorting between the third and fifth 52, 56 layers on therespective blades 24, 26.

With further reference to FIG. 5, the electrically insulating materialof the second and fourth layers 50, 54 of the first and second scissorblades 24, 26 has sufficient dielectric strength to substantiallyprevent electrical breakdown of the insulating material. The exposedsurfaces 58 of the third layer 52 of the first and second blades 24, 26may form at least two first electrodes 44 on each of the first andsecond blades. The exposed surfaces 60 of the fifth layer 56 of thefirst and second blades 24, 26 may form at least one second electrode 46on each of the first and second blades. As depicted in FIG. 5, theexposed surfaces 60 of the fifth layer 56 of the first and second blades24, 26 may form one second electrode 46 positioned between the at leasttwo first electrodes 44 on each of the first and second blades. Theshearing surfaces 28 and cutting edges 32 of the first and second blades24, 26 may include a coating, such as a coating of amorphousdiamond-like carbon or other suitable material that is well known in theart, to resist mechanical wear and friction between the blades.

Referring to FIG. 6, the first and/or second scissor blade 24, 26 mayinclude an insulating body with a shearing layer and electrodes coupledto the insulating body. In other embodiments, the first and secondblades 24, 26 may include an insulating body with a shearing layercoupled to the insulating body and electrodes inlayed into theinsulating body (FIG. 7), electrodes deposited onto the insulating body(FIG. 8), or include suitable electrodes in any other form that is wellknown in the art positioned on the insulating body. More particularly,each of the first and second blades 24, 26 includes an insulating body70 having a primary surface 72 corresponding with the shearing surface28, and a secondary surface 74 corresponding with the opposed surface30. A shearing layer 76 is coupled to the primary surface 72 of theinsulating body 70. The shearing layer 76 includes a first, shearingsurface 28, a second, opposed surface 78, and the cutting edge 32. Thesecond, opposed surface 78 of the shearing layer 76 is coupled to theprimary surface 72 of the insulating body 70.

With continued reference to FIGS. 6-8, as the shearing layer 76 includesthe shearing surface 28 and cutting edge 32 of the blades 24, 26, theshearing layer is made of a material capable of forming a desirablecutting edge, such as a metal or other material that is well known inthe art. As stated above, the shearing surface 28 of each of the firstand second blades 24, 26 is electrically neutral. Thus, the shearinglayer 76 is not coupled to either of the first or second electricalconnections 40, 42.

With further reference to FIGS. 6-8, the first scissor blade 24 mayinclude the at least one first electrode 44 and the at least one secondelectrode 46 coupled to (FIG. 6), inlayed into (FIG. 7), or depositedonto (FIG. 8) the secondary surface 74 of the insulating body 70 of thefirst blade with the first and second electrodes positioned in analternating relationship. The second scissor 26 blade may include the atleast one first electrode 44 and the at least one second electrode 46coupled to (FIG. 6), inlayed into (FIG. 7), or deposited onto (FIG. 8)the secondary surface 74 of the insulating body 70 of the second bladewith the first and second electrodes positioned in an alternatingrelationship and corresponding to the first and second electrodes on thefirst blade. The electrically insulating material of which theinsulating body 70 of the first and second scissor blades 24, 26 isformed has sufficient dielectric strength to substantially preventelectrical breakdown of the electrically insulating material.

Referring to FIG. 9, the first and/or second scissor blade 24, 26 mayinclude a laminated structure similar to the laminated structure of FIG.5 with each of the first and second scissor blades 24, 26 including atleast the first layer 48, the second layer 50, the third layer 52, thefourth layer 54 and the fifth layer 56. FIG. 9 depicts each of the tofirst and second scissor blades 24, 26 including the laminatedstructure.

Similar to FIG. 5, the first layer 48 of FIG. 9 coincides with theshearing surface 28 and cutting edge 32 of the blades 24, 26. The firstlayer 48 includes the first, shearing surface 49 and second, opposedsurface 51, and is made of a material capable of forming a desirablecutting edge, such as a metal or other materials that are well known inthe art. The first layer 48 also includes a first and second edgesurface 80, 82 with each edge surface including a first electrode 44.The first electrodes 44 on the first and second edge surfaces 80, 82 ofthe first blade 24 are coupled to the first electrical connection 40(FIG. 1) and the first electrodes 44 on the first and second edgesurfaces 80, 82 of the second blade 26 are coupled to the secondelectrical connection 42 (FIG. 1). The first edge surface 80 of thefirst layer 48 of each of the first and second blades 24, 26 coincideswith the cutting edge 32 of the blades.

The second layer 50 of each of the first and second scissor blades 24,26 is coupled to the second surface 51 of the first layer 48. The thirdlayer 52 is coupled to the second layer 50 on the side opposite thefirst layer 48. The third layer 52 is electrically conductive. Thefourth layer 54 is coupled to the third layer 52 on the side oppositethe second layer 50. The fifth layer 56 is coupled to the fourth layer54 on the side opposite the third layer 52. The fifth layer 56 iselectrically conductive.

With continuing reference to FIG. 9, the third layer 52 of each of thescissor blades 24, 26 includes exposed portions 58 that form the atleast one second electrode 46 of the first and second blades. The thirdlayer 52 on the first blade 24 is coupled to the second electricalconnection 42 (FIG. 1) and the third layer 52 on the second blade 26 iscoupled to the first electrical connection 40 (FIG. 1). The second layer50 completely separates the third, conductive layer 52 from the first,conductive layer 48.

The fifth layer 56 includes exposed portions 60 that form another firstelectrode 44 on each of the first and second scissor blades 24, 26. Thefifth layer 56 on the first blade 24 is coupled to the first electricalconnection 40 (FIG. 1) and the fifth layer 56 on the second blade 26 iscoupled to the second electrical connection 42 (FIG. 1). The fourthlayer 54 completely separates the fifth, conductive layer 56 from thethird, conductive layer 52.

The third layer 52 has opposing polarity to the first and fifth layers48, 56. The second and fourth layers 50, 54 are electricallynonconductive and are formed of materials that insulate againstelectrical current to prevent electrical shorting between the thirdlayer 52 and the first and fifth layers 48, 56 on the respective blades.

With further reference to FIG. 9, the electrically insulating materialof the second and fourth layers 50, 54 of the first and second scissorblades 24, 26 has sufficient dielectric strength to substantiallyprevent electrical breakdown of the insulating material. The exposedsurfaces 58 of the third layer 52 of the first and second blades 24, 26may form at least two second electrodes 46 on each of the first andsecond blades. The exposed surfaces 60 of the fifth layer 56 of thefirst and second scissor blades 24, 26 may form at least one firstelectrode 44 on each of the first and second scissor blades. As depictedin FIG. 9, the exposed surfaces 60 of the fifth layer 56 of the firstand second scissor blades 24, 26 may form one first electrode 44positioned between the at least two second electrodes 46 on each of thefirst and second blades.

With the first layer 48 of the first scissor blade 24 being coupled tothe first electrical connection 40 and the first layer 48 of the secondscissor blade 26 being coupled to the second electrical connection 42,it is necessary to electrically insulate the mating and interfacingportions of the first layer of each of the blades to prevent electricalshorting between the blades. Referring to FIG. 9, the shearing surfaces28 and cutting edges 32 of each of the first and second blades 24, 26may include an electrically insulating coating 84, such as a coating ofamorphous diamond-like carbon or other suitable electrically insulatingmaterial that is well known in the art. An amorphous diamond-likecoating facilitates the prevention of electrical shorting throughmetallic blades 24, 26 and resists mechanical wear and friction betweenthe blades. On each of the first and second scissor blades 24, 26,portions of the first edge surface 80 and the second edge surface 82proximate the shearing surface 28 are also coated with the electricallyinsulating coating 84 to facilitate the prevention of electricalshorting through the blades. The portions of the first edge surface 80and the second edge surface 82 that are proximate the second, opposedsurface 51 of each of the first and second scissor blades 24, 26 are notcovered with the electrically insulating coating 84 and, thereby,function as first electrodes 44 for each of the scissor blades.

FIGS. 10-12 are similar to FIGS. 6-8, respectively Referring to FIGS.10-12, the first and/or second scissor blade 24, 26 may include aninsulating body with a shearing layer coupled to the insulating body.The first and second blades 24, 26 may include electrodes coupled to theinsulating body (FIG. 10), electrodes inlayed into the insulating body(FIG. 11), electrodes deposited onto the insulating body (FIG. 12), orinclude suitable electrodes in any other form that is well known in theart positioned on the insulating body.

Similar to FIGS. 6-8, each of the first and second scissor blades 24, 26of FIGS. 10-12 includes the insulating body 70 having the primarysurface 72 corresponding with the shearing surface 28, and the secondarysurface 74 corresponding with the opposed surface 30. The shearing layer76 is coupled to the primary surface 72 of the insulating body 70. Theshearing layer 76 includes the first, shearing surface 28, the second,opposed surface 78, and the cutting edge 32. The shearing layer 76 alsoincludes the first and second edge surface 80, 82 with each of the edgesurfaces including a first electrode 44. The first electrodes 44 on thefirst and second edge surfaces 80, 82 of the first scissor blade 24 arecoupled to the first electrical connection 40 (FIG. 1) and the firstelectrodes 44 on the first and second edge surfaces 80, 82 of the secondscissor blade 26 are coupled to the second electrical connection 42(FIG. 1). The first edge surface 80 of the shearing layer 76 of each ofthe first and second blades 24, 26 coincides with the cutting edge 32 ofthe blades. The second, opposed surface 78 of the shearing layer 76 iscoupled to the primary surface 72 of the insulating body 70.

With continued reference to FIGS. 10-12, as the shearing layer 76includes the shearing surface 28 and cuffing edge 32 of the blades 24,26, the shearing layer is made of a material capable of forming adesirable cutting edge, such as a metallic material or other materialthat is well known in the art. With the shearing layer 76 of the firstscissor blade 24 being coupled to the first electrical connection 40(FIG. 1) and the shearing layer 76 of the second scissor blade 26 beingcoupled to the second electrical connection 42 (FIG. 1), it is necessaryto electrically insulate the mating and interfacing portions of theshearing layer of each of the blades to prevent electrical shortingbetween the blades. Referring to FIGS. 10-12, the shearing surfaces 28and cutting edges 32 of the shearing layers 76 of each of the first andsecond scissor blades 24, 26 may include an electrically insulatingcoating 84, such as a coating of amorphous diamond-like carbon or othersuitable electrically insulating material that is well known in the art.On each of the first and second scissor blades 24, 26, portions of thefirst edge surface 80 and the second edge surface 82 proximate theshearing surface 28 are also coated with the electrically insulatingcoating 84. The portions of the first edge surface 80 and the secondedge surface 82 that are proximate the second, opposed surface 78 ofeach of the first and second blades 24, 26 are not covered with theelectrically insulating coating 84 and, thereby, function as firstelectrodes 44 for each of the blades. Alternatively, depending onselective uses for the scissors, the shearing layer 76 on each of thefirst and second blades 24, 26 may include a first electrode 44 on onlyone of the first and second edge surfaces 80, 82.

With further reference to FIGS. 10-12, the first scissor blade 24 mayinclude at least one first electrode 44 and at least one secondelectrode 46 coupled to (FIG. 10), inlayed into (FIG. 11), or depositedonto (FIG. 12) the secondary surface 74 of the insulating body 70 of thefirst blade with the first and second electrodes positioned in analternating relationship. The second scissor 26 blade may include atleast one first electrode 44 and at least one second electrode 46coupled to (FIG. 10), inlayed into (FIG. 11), or deposited onto (FIG.12) the secondary surface 74 of the insulating body 70 of the secondscissor blade with the first and second electrodes positioned in analternating relationship and corresponding to the first and secondelectrodes on the first scissor blade. The electrically insulatingmaterial of which the insulating body 70 of the first and second scissorblades 24, 26 is formed has sufficient dielectric strength tosubstantially prevent electrical breakdown of the electricallyinsulating material.

On each of the first and second scissor blades 24, 26, the distancebetween the at least one first electrode 44 and the at least one secondelectrode 46 is sufficient to prevent electrical arcing between theelectrodes. At the same time, the distance between the at least onefirst electrode 44 and the at least one second electrode 46 is smallenough to permit simultaneous connection between the tissue 22 and tworespective electrodes 44, 46 having opposing polarity (see FIG. 13).With the scissors 20 in a closed condition (FIG. 14), the distancebetween the first electrodes 44 on the first scissor blade 24 at thefirst and second edge surfaces 80, 82 and the first electrodes 44 on thesecond scissor blade 26 at the first and second edges 80, 82 issufficient to prevent electrical arcing between the first electrodes onthe first blade and the first electrodes on the second blade. At thesame time, the distance between the first electrodes 44 on the firstblade 24 and the first electrodes 44 on the second blade 26 is smallenough to permit simultaneous connection between the tissue 22 and thefirst electrodes, which have opposing polarity, on adjacent edgesurfaces 80, 82 of the shearing layers 76 of the first and secondblades.

The bipolar electrosurgical scissors 20 of the present invention may beused for numerous surgical functions, including functions that havetypically been reserved for monopolar surgical devices. For example, inthe first energized state, as discussed above, the scissors 20 may beused to coagulate tissue 22 between the first and second scissor blades24, 26 prior to mechanically cutting the tissue (see FIGS. 2 and 15).The scissors 20 are positioned in an open condition with the tissue 22between the open blades 24, 26 In the first energized state, the firstelectrical connection 40 (FIG. 1) delivers electrical current only tothe at least one first electrode 44 on the first scissor blade 24 andthe second electrical connection 42 (FIG. 1) delivers electrical currentonly to the at least one first electrode 44 on the second scissor blade26. The current travels mainly between the activated electrodes 44,thereby coagulating the tissue 22 between the open blades 24, 26 priorto the tissue being cut.

Referring to FIGS. 4 and 16, in the second energized state, wherein allof the first and second electrodes 44, 46 on the first and secondscissor blades 24, 26 are energized, the tissue 22 surrounding thetissue being mechanically cut is coagulated. In the second energizedstate, the tissue 22 being cut may also be coagulated in addition tocoagulation of the tissue that is surrounding the tissue being cut.Referring to FIG. 13, in the second energized state the opposed surface30 of one of the first and second scissor blades 24, 26 may be appliedto tissue 22 to coagulate the tissue, similar to as is done withmonopolar surgical devices. As stated above, the first and secondelectrodes 44, 46 are positioned such that each of a first and secondelectrode on one of the first and second scissor blades 24, 26 may be incontact with the tissue 22 at the same time. Referring to FIG. 14, inthe first energized state with the scissors 20 in a closed condition,adjacent first electrodes on the edge surfaces 80, 82 of the shearinglayers 76 of the first and second scissor blades 24, 26 may be movedacross the tissue 22 in a sweeping motion to electrically dissect thetissue, similar to as is done with monopolar surgical devices.Alternatively, referring to FIG. 17, in the second energized state theopposed surface 30 of one of the first and second scissor blades 24, 26may be moved across the tissue 22 in a sweeping motion to electricallydissect the tissue.

Although this invention has been disclosed with reference to certainstructural configurations, it will be appreciated that these productsare merely representative of many different embodiments of theinvention. Accordingly, one is cautioned not to limit the concept onlyto the disclosed embodiments, but rather encouraged to determine thescope of the invention only with reference to the following claims.

1. A bipolar electrosurgical scissors for use in treating biologicaltissue, comprising: a first scissor blade including a shearing surface,an opposed surface opposite the shearing surface, and a cutting edge,the shearing surface and cutting edge being electrically neutral; asecond scissor blade pivotally coupled to the first blade, the secondblade including a shearing surface, an opposed surface opposite theshearing surface, and a cutting edge, the shearing surface and cuttingedge being electrically neutral; a first electrical connection forreceiving an electrical current of a first polarity; a second electricalconnection for receiving an electrical current of a second polarity, thesecond polarity being opposite the first polarity; at least one firstelectrode positioned on the opposed surface of the first scissor bladeand coupled to the first electrical connection; at least one secondelectrode positioned on the opposed surface of the first scissor bladeand coupled to the second electrical connection; at least one firstelectrode positioned on the opposed surface of the second scissor bladeand coupled to the second electrical connection; and at least one secondelectrode positioned on the opposed surface of the second scissor bladeand coupled to the first electrical connection, in a first energizedstate, the first electrical connection delivers electrical current onlyto the at least one first electrode on the first scissor blade and thesecond electrical connection delivers electrical current only to the atleast one first electrode on the second scissor blade, and in a secondenergized state, the first electrical connection delivers electricalcurrent to the at least one first electrode on the first scissor bladeand to the at least one second electrode on the second scissor blade andthe second electrical connection delivers electrical current to the atleast one second electrode on the first scissor blade and to the atleast one first electrode on the second scissor blade.
 2. The bipolarelectrosurgical scissors of claim 1, wherein the at least one firstelectrode on the opposed surface of the first scissor blade extendslengthwise along a length of the first scissor blade.
 3. The bipolarelectrosurgical scissors of claim 1, wherein: the distance between theat least one first electrode and the at least one second electrode onthe opposed surface of the first scissor blade is sufficient to preventelectrical arcing between the electrodes, and small enough to permitsimultaneous connection between the tissue and two respective electrodeshaving opposing polarity; and the distance between the at least onefirst electrode and the at least one second electrode on the opposedsurface of the second scissor blade is sufficient to prevent electricalarcing between the electrodes, and small enough to permit simultaneousconnection between the tissue and two respective electrodes havingopposing polarity.
 4. The bipolar electrosurgical scissors of claim 1,each of the first and second scissor blades comprising: an insulatingbody having a primary surface corresponding with the shearing surface ofthe blade and a secondary surface corresponding with the opposed surfaceof the blade; a shearing layer having a first, shearing surface, asecond, opposed surface, and the cutting edge, the opposed surface ofthe shearing layer being coupled to the primary surface of theinsulating body; and the at least one first electrode and the at leastone second electrode being coupled to the secondary surface of theinsulating body of each of the first and second scissor blades.
 5. Thebipolar electrosurgical scissors of claim 4, wherein the first andsecond electrodes are positioned in an alternating relationship with thefirst and second electrodes on the second scissor blade correspondingwith the first and second electrodes on the first scissor blade.
 6. Thebipolar electrosurgical scissors of claim 4, wherein a material formingthe electrically insulating body of the first and second scissor bladeshas sufficient dielectric strength to substantially prevent electricalbreakdown of the electrically insulating body.
 7. The bipolarelectrosurgical scissors of claim 1, wherein the first scissor bladefurther comprises a third electrode positioned adjacent the shearingsurface, the third electrode coupled to the first electrical connection,and wherein the shearing surface is formed of an electrically insulatingcoating; and wherein the second scissor blade further comprises a thirdelectrode positioned adjacent the shearing surface, the third electrodecoupled to the second electrical connection, and wherein the shearingsurface is formed of an electrically insulating coating.
 8. A bipolarelectrosurgical scissors for use in treating biological tissue,comprising: a first scissor blade including a shearing surface, anopposed surface opposite the shearing surface, and a cutting edge, theshearing surface and cutting edge of the first scissor blade beingelectrically neutral; and a second scissor blade pivotally coupled tothe first scissor blade, the second scissor blade including a shearingsurface, an opposed surface opposite the shearing surface, and a cuttingedge, the shearing surface and cutting edge of the second scissor bladebeing electrically neutral, the shearing surface of the second scissorblade facing the shearing surface of the first scissor blade andinterfacing with the shearing surface of the first scissor blade; eachof the first and second scissor blades including a laminated structurecomprising: a first layer coinciding with the shearing surface andcutting edge of the scissor blade, the first layer including a firstsurface and a second, opposed surface opposite the first surface, thefirst surface of the first layer forming the shearing surface of theblade; a second layer coupled to the second surface of the first layer,the second layer being electrically nonconductive, a third layer coupledto the second layer on the side opposite the first layer with the secondlayer completely separating the third layer from the first layer, thethird layer being electrically conductive and forming at least one firstelectrode at exposed portions thereof, a fourth layer coupled to thethird layer on the side opposite the second layer, the fourth layerbeing electrically nonconductive, and a fifth layer coupled to thefourth layer on the side opposite the third layer with the fourth layercompletely separating the fifth layer from the third layer, the fifthlayer being electrically conductive and forming at least one secondelectrode at exposed portions thereof.
 9. The bipolar electrosurgicalscissors of claim 8, further comprising: a first electrical connectionfor receiving an electrical current of a first polarity; and a secondelectrical connection for receiving an electrical current of a secondpolarity, the second polarity being opposite the first polarity; andwherein the first electrical connection is coupled to the at least onefirst electrode on the first scissor blade and to the at least onesecond electrode on the second scissor blade; and wherein the secondelectrical connection is coupled to the at least one second electrode onthe first scissor blade and to the at least one first electrode on thesecond scissor blade.
 10. The bipolar electrosurgical scissors of claim9, wherein in a first energized state, the first electrical connectiondelivers electrical current only to the at least one first electrode onthe first scissor blade and the second electrical connection deliverselectrical current only to the at least one first electrode on thesecond scissor blade; and wherein in a second energized state, the firstelectrical connection delivers electrical current to the at least onefirst electrode on the first scissor blade and to the at least onesecond electrode on the second scissor blade and the second electricalconnection delivers electrical current to the at least one secondelectrode on the first scissor blade and to the at least one firstelectrode on the second scissor blade.
 11. The bipolar electrosurgicalscissors of claim 9, wherein the first layer of the first scissor bladeis electrically neutral, and wherein the first layer of the secondscissor blade is electrically neutral.
 12. The bipolar electrosurgicalscissors of claim 8, further comprising an electrically insulatingcoating disposed on the first surface of the first layer of each of thefirst and second scissor blades.
 13. The bipolar electrosurgicalscissors of claim 12, wherein the first layer of each of the first andsecond scissor blades is electrically conductive and forms at least onethird electrode at exposed portions thereof.
 14. The bipolarelectrosurgical scissors of claim 13, further comprising a firstelectrical connection for receiving an electrical current of a firstpolarity; and a second electrical connection for receiving an electricalcurrent of a second polarity, the second polarity being opposite thefirst polarity; and wherein the first electrical connection is coupledto the at least one first electrode on the first scissor blade, to theat least one third electrode on the first scissor blade, and to the atleast one second electrode on the second scissor blade; and wherein thesecond electrical connection is coupled to the at least one secondelectrode on the first scissor blade, to the at least one firstelectrode on the second scissor blade, and to the at least one thirdelectrode on the second scissor blade.
 15. The bipolar electrosurgicalscissors of claim 14, wherein in a first energized state, the firstelectrical connection delivers electrical current only to the at leastone third electrode on the first scissor blade and the second electricalconnection delivers electrical current only to the at least one thirdelectrode on the second scissor blade.
 16. A bipolar electrosurgicalscissors for use in treating biological tissue, comprising: a firstscissor blade having a shearing surface, and an opposed surface oppositethe shearing surface, the first scissor blade comprising: at least onefirst electrode positioned on the opposed surface; and at least onesecond electrode positioned on the opposed surface; a second scissorblade pivotally coupled to the first scissor blade by a pivot pin, thesecond scissor blade having a shearing surface and an opposed surfaceopposite the shearing surface, the second scissor blade comprising: atleast one first electrode positioned on the opposed surface; and atleast one second electrode positioned on the opposed surface; andwherein in a first energized state, electrical current of a firstpolarity is delivered only to the at least one first electrode on thefirst scissor blade and electrical current of a second polarity oppositethe first polarity is delivered only to the at least one first electrodeon the second scissor blade, and in a second energized state, electricalcurrent of the first polarity is delivered to the at least one firstelectrode on the first scissor blade and to the at least one secondelectrode on the second scissor blade and electrical current of thesecond polarity is delivered to the at least one second electrode on thefirst scissor blade and to the at least one first electrode on thesecond scissor blade.
 17. The bipolar electrosurgical scissors of claim16, wherein the shearing surfaces of the first scissor blade and thesecond scissor blade are electrically neutral.
 18. The bipolarelectrosurgical scissors of claim 16, wherein the shearing surfaces ofthe first scissor blade and the second scissor blade each comprise anelectrically insulating coating.
 19. The bipolar electrosurgicalscissors of claim 16, wherein the first scissor blade is formed of alaminated construction comprising a plurality of layers, and wherein thesecond scissor blade is formed of a laminated construction comprising aplurality of layers.
 20. The bipolar electrosurgical scissors of claim16, wherein the first scissor blade further comprises an insulating bodyhaving a primary surface corresponding with the shearing surface of theblade and a secondary surface corresponding with the opposed surface ofthe blade.
 21. The bipolar electrosurgical scissors of claim 16, whereinthe first scissor blade comprises two first electrodes and one secondelectrode.